High reliability electrolytic capacitors
03 April 2013
Electronic products are at the heart of almost all everyday activities that affect our lives - products ranging from simple disposal aids that are only expected to last for the warranty period, to critical safety devices that would be expected to last the life of the system and most certainly significantly longer than any manufacturers’ warranty period.
An electronic component that can cause major reliability problems in electronic circuits is the electrolytic capacitor. This device is not often seen as a weak point in circuit design but it does have a critical task to perform in almost all circuitry, particularly in power supplies or where a point of power transfer is required.
Electrolytic capacitors are simple devices that many companies can manufacture but only a few have experience of, and control over the critical constituent parts of these devices that make zero-defect, high reliability capacitors.
Nippon Chemi-Con is such a vertically integrated electrolytic capacitor manufacturer. Based in Japan and with over 80 years of capacitor technology experience, the company supplies the highest quality and longest operating life components to the world’s most discerning electronic equipment manufacturers.
Young Electronics Group (YEG) has supplied over 90 million of Nippon Chemi-Con's electrolytic capacitors to the UK electronics manufacturing sector over the last four years with no known defect, product return or circuit failure.
During the past six years YEG has shipped over 129 million pieces and experienced just six returns for a manufacturing defect. This issue was due to some microscopic scratching within the aluminium can of a particular capacitor.
Subsequently, Nippon Chemi-Con stopped using sub-contracted aluminium can manufacture and brought the process into their own manufacturing facilities.
Another statistical parameter that defines a world class manufacturing organisation is the drive to reduce the number of end-of-line failures, or for a process to achieve zero defects. Nippon Chemi-Con has year on year driven down the end of line defects. These reject levels have improved from 16 defect parts in 108 produced during the early 1990s to less than 40 defect parts in 109 produced by the end of 2011.
Looking at the expected operating life or field failures and MTBF of Nippon Chemi-Con electrolytic capacitors we can take a typical factory FIT figure for a particular series such as a KXJ radial can which is stated to be 38.2 FIT at +65C, now the latest edition of the MIL-HDBK-217C shows that an electrolytic capacitor is generally assigned a FIT figure of 100 X 2.08 = 208 FIT at +65C.
Nippon Chemi-Con’s fully integrated manufacturing cycle ensures that the etched aluminium foil, controlled layers of oxide dielectric and voltage forming are continuously being refined in irder to maximise the final effective capacitance area. This process drives down size the capacitors while increasing the capacitance, or maintains the capacitance values and ripple current rating in a smaller can size.
The rubber sealing devices, aluminium cans for all sizes and type of capacitor body, and the liquid electrolytes are all manufactured in-house, as is the fully automatic core winding, foil stitching, electrolyte filling, can sealing and product testing.
YEG supplies these high reliability components for use in aerospace, automotive safety and critical control systems, medical equipment, rail, defence and industrial process control systems and sub-assemblies. For more information about YEG's capacitor offfering, click here.